<!DOCTYPE html>
<html>
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>代理与内部槽位</title>
</head>
<body>
  <script>
    const target = new Date();
    const proxy = new Proxy(target, {});

    console.log(proxy instanceof Date);  // true

    proxy.getDate();  // TypeError: 'this' is not a Date object
  </script>
</body>
</html>